1. Field of the Invention
The present invention relates to a splash shield for an automobile that covers regions above a tire in order to shield vehicle panels against muddy water and the like that is splashed by the tire when the automobile is running.
2. Description of the Related Art
Typically, a portion of a vehicle panel that covers the upper surface of a tire of an automobile forms an arch-shaped wheelhouse that receives a tire. A splash shield, which is made of synthetic resin and which is formed in conformity with the vehicle panel, is mounted on the wheelhouse. The splash shield is provided to protect the vehicle panel against objects, such as muddy water, small stones, ice, snow and the like, that are splashed by the tire when the automobile runs on a rough road or on a wet road, and to prevent such objects from intruding into the inside space of the vehicle panel.
A splash shield of this type is manufactured by forming a composite material, which is made of thermoplastic resin, such as polyethylene resin, and which contains various types of fillers mixed therewith, into a sheet shape, and then by performing vacuum forming or air pressure forming or the like. Thus, a splash shield is formed into a shape that conforms to the shape of a wheelhouse, which is the portion of a vehicle panel on which the splash shield is mounted, and is then fixed to the vehicle panel by means of screws, small screws, clips or the like.
When vacuum forming or air pressure forming is performed, portions of the resin sheet that are subjected to deep drawing tend to be thinner than other portions after the forming process is finished even if the resin sheet has a uniform thickness before forming. Accordingly, when an arch-shaped splash shield that extends along the upper portion of a tire is simply formed in an integral member, end portions of the splash shield that are subjected to deep drawing tend to be thinned. This tendency is remarkable especially for a splash shield for a large automobile because such a splash shield has a larger arc diameter and a larger height when it is finished. Therefore, it is desirable to limit a reduction in thickness that is caused by the forming process, and thereby to prevent a reduction in stiffness, breakage and deformation of the portion that is thinned. The finished product having a large height is also problematic because the size of a mold, as well as manufacturing cost, would be increased.
As a solution to these problems, a technique is known in which a splash shield is formed by combining a plurality of members that are divided in the front-rear direction of an automobile. Japanese Patent Publication No. 72314/93 discloses a further advanced art for a splash shield, as shown in FIG. 1. Splash shield 100 has front-side splash shield 101 and rear-side splash shield 102 that are connected to each other by means of connecting member 103 in the form of a generally flat plate. Specifically, on both sides of splash shields 101, 102, gaps are formed between adjacent side walls that extend in the direction of the tire radius. The portion between the gaps forms connecting member 103. Flange 106 is formed on the side wall such that it projects in the axial direction of the tire and extends along the lower side of the side wall. Through holes 105, which allow screws for fixing the splash shields to a wheelhouse to be inserted, are formed in flange 106. Flange 106 is also divided to form a gap at a position that corresponds to connecting member 103.
Splash shield 100 can allow front-side splash shield 101 and rear-side splash shield 102 to be pivoted relative to each other about connecting member 103 by means of flat connecting member 103. Accordingly, splash shield 100 is formed in an open state with regard to the front-rear direction. This allows a reduction in the height of the finished product. When splash shield 100 is mounted after forming, splash shield 100 is deformed about connecting member 103, and is put in a retracted state with regard to the front-rear direction to conform to the shape of the wheelhouse, as indicated by arrow E in FIG. 1. The gaps between front-side splash shield 101 and rear-side splash shield 102 are thus closed. Overlapped portions between front and rear flanges 106 are fixed to each other by means of screws so that splash shield 100 is mounted in a state in which the gaps are closed.
Japanese Utility Model Publication No. 52145/92 discloses various hinge structures for pivotably connecting portions of a splash shield that are divided in the front-rear direction.
It is desirable for a splash shield for an automobile to prevent foreign objects, such as muddy water, snow and blocks of ice, from intruding into space between the splash shield and the vehicle panel that forms the wheelhouse. This leads to limitation of noise that is caused by foreign objects that intrude into the space, as well as limitation of interference of the splash shield with the tire that is caused by pulling down of the splash shield. To achieve this purpose, a structure having a vertical wall that is connected to an edge of a side wall of a splash shield is known. This vertical wall is turned about the edge of the side wall and extends about an edge of the vehicle panel.
However, if such a vertical wall is applied to the above-mentioned splash shield having portions that are divided in the front-rear direction and that are pivotably connected to each other, then the vertical walls that are formed on the respective divided portions move away from each other due to a pivoting motion during the mounting process. Therefore a large gap is inevitably left between the vertical walls. This gap impairs the effect of limiting intrusion of muddy water, snow and blocks of ice.
Further, when a splash shield having portions that are divided in the front-rear direction and that are connected to each other by means of a hinge is used, it is preferable to limit fluttering of the hinge that may be caused by wind pressure during operation of the automobile, even if the hinge is formed, in particular, in the vicinity of the end portion of the splash shield. This leads to limitation of noise and prevents muddy water, snow and the like from intruding through the gap that is generated by fluttering. To cope with this problem, the number and the interval of fixing means, such as bolts, on the vehicle panel are suitably determined. However, particularly when the above-described vertical wall is used, it is not desirable to provide the vehicle panel with openings for the fixing means from the viewpoint of soundproof. It is even impossible, in some cases, to provide such openings because of the structure of the vehicle panel.
There is a need for other measures to limit fluttering.